This invention relates to methods and arrangements for controlling the exhaust emissions from an internal combustion engine having a particle filter in an exhaust gas line for filtering solid particles from the exhaust gas.
German Offenlegungsschrift No. 38 21 138 discloses filtration and postcombustion of the solid particles, or soot, in a particle filter and utilization of the heat energy obtained therefrom for the heating of a vehicle interior but no recirculation of the exhaust gases of the internal combustion engine is provided.
A similar arrangement is disclosed in U.S. Pat. No. 4,991,396. This arrangement also has a burner for regenerating the soot filter and the heat energy produced in the burner is likewise used for heating and vehicle interior when the engine exhaust gases do not provide sufficient heat for heating the vehicle.
In both those disclosures, the exhaust gases from burning of the solid particles are released into the environment.
German Offenlegungsschrift No. 42 34 841 and German Patent No. 43 40 463 describe internal combustion engines having a soot filter which is regenerated and also describe recirculation of exhaust gas from the engine. In these arrangements, however, burning of the soot particles takes place in the soot filter, having the disadvantage that the burning is uncontrolled and explosive. In addition, the gases produced by burning of the particles are released into the environment.